Apparatus for combating acceleration nausea



No 9, 1943. R. MAYNE 2,334,018

APPARATUS FOR COMBATING ACCELERATION NAUSEA Filed Sept. 25, 1939 v 2Sheets-Sheet 1 INV ENTOR 7 E0647 May/7a ATTORNEY Nov. 9, 1943. R. MAYNE2,334,018

APPARATUS FOR COMBATING ACCELERATION NAUSEA File d Sept. 25, 1959 2Sheets-Sheet 2 77 Fig: &

STABILIZED oscnurol' Autumn-g INVENTOR Ewe/f May/7c. BY 4 ,7

ATTORNEY Patented Nov. 9, 1943 UNITED STATES. PATENT OFFICE APPARATUSFOR COMBATING 1 ACCELERATION NAUSEA Robert Mayne, Akron, OhioApplication September 23, 1939, Serial No. 296,281

to some extent unpredictable, as to direction or as Claims.

This invention relates to methods and apparatus for preventing, orlessening the discomfort of, acceleration nausea, commonly calledseasickness.

My chief objects are clearly indicated in that statement.

A further object is to provide procedure and apparatus such as to givepleasure in place of the discomfort of acceleration nausea.

It is well known that acceleration nausea, in varying degrees from thatof a merely incipient state of discomfort to that of extreme illness, isexperienced by many persons not only upon the sea but also in airplanes,in land vehicles and even in rapidly accelerating elevators.

It is also well known that the accelerometer action of the inner ear isin some way the cause of the disturbance of the nervous system and ofthe resultin discomfort. Changes of stresses in other parts of the bodymay also be a cause.

My invention is based upon the belief that the nausea results from thefutility of an instinctive attempt of the nervous system to rid itselfof an unfamiliar, uncorrelated and consequently weird or uncanny andrepugnant sensation resulting from unwilled or unapprehended ornon-correlated or unpredictable acceleration.

In ordinary human activities the body experiences many positiveaccelerations and many negative accelerations or decelerations withoutnausea resulting, as in the increase of speed in .valking or running orin leaping down from a heigh or diving or in driving an automobile or ina swing.

But in those instances the positive and negative accelerations areaccompanied by other phenomena which are observable through othersenses, such as those of seeing, hearing and feeling.

Thus the body has learned to associate the sense of acceleration withother sensual stimuli in familiar or experienced patterns.

In ordinary activities, also, the accelerations are not contrary to thewill of the individual, and are closely predictable, so that there is noelement of surprise or of helplessness. The sense of acceleration isfitted into a familiar experienced pattern of stimuli and the harmony ofthe pattern may even appeal to the aesthetic sense, with resultantpleasure.

On the other hand, under the conditions which produce seasickness, theaccelerations are not adequately correlated with other phenomenaproviding stimuli of the senses to provide a familiar pattern ofstimuli, and thus be apprehended instead of being incongruous or weird,or they are to intensity, or they are not under the immediate control ofthe individual, however much he may try to hold up the plane with hisstomach" or to steady the ship by means of the same futileinstrumentality.

The lack of correlation is, of these three, possibly the most importantfactor, or the most generally effective factor, in causing seasickness,although the other two, unpredictable character and uncontrollablecharacter, may be strong factors in the cases of some individuals, andthey also are taken into account in the practice of my invention in someof its applications.

An illustrative instance of the lack of adequate correlation is that ofa passenger aboard a rolling ship. The stimuli of the sense of sight areinadequately correlated with the stimuli of the sense of acceleration ashe watches the water or the horizon in an attempt at correlation,because of the fact that velocity and acceleration are wholly differentthings. Acceleration may be greatest, in any one of the threedimensions, when the velocity in that dimension is least, and velocitymay be greatest when acceleration is least. The relative movement of thewater or of the horizon, quite observable as to velocity, is notadequately observable as to acceleration.

The velocity and the acceleration are not at all in step, andconsequently the correlation of the sensual stimuli is in many instancesnot adequate for making the sense of acceleration fit into a familiar orexperienced pattern of sensations and thu seem natural or comprehensibleinstead of incongruous and therefore repugnant, inharmonious andtherefore not aesthetic, or inapprehensible and therefore weird.

I attain the objects of my invention primarily by providing sensuallyobservable phenomena having definite relation to the acceleration.

In so doing, I make it possible for the individual to lessen the effectof each of the three above mentioned factors in the production ofseasickness, by (1) learning to predict or anticipate the accelerationsto a gratifying extent, as to direction and preferably also as tointensity, (2) to apply his skill to the absorbing occupation ofmanifesting his predictions or his quick reactions by manuallynullifying or closely following a recorded effect of the accelerations,and thus ease his nervous system against its instinctive effort to riditself of an inexperienced pattern of stimuli, or to acquire agratifying sense of mastery, and (3), perhaps the most generallyhelpful, to correlate the sense of acceleration with one or more of theother senses, so that the pattern of stimuli will become an experiencedor familiar pattern, with a non-repugnant or even an aesthetic feelingas the result.

On the theory that the greatest repugnance results from the greatestincongruity or dis-harmony and that the greatest aesthetic pleasureresults from the contemplation of a system or a pattern having thelargest number of harmonious elements that the individual can easilypredict or apprehend and correlate, it may be desirable in someinstances to provide harmonious or correlated stimuli to several of thesenses at the same time, but my invention is not wholly limited to that,as the correlation of a single sense, such as that of sight, of hearing,or of feeling, is suillcient and possibly preferable, for accomplishingthe primary purpose of the invention, in many cases.

The sensually observable effects of the acceleration may be of varioustypes, preferred examples being:

1. Variations in the dimensional relations of objects or images asobserved visually, such as variation of the position of a beam of lighton a screen in relation to a spot on thescreen.

2. Variations in the speed of a motion, such as that of a beam of light,on a screen, moving on the screen in definite relation to the speed anddirection of the observers movement with relation to the earth.

3. Variations in dimensional relations as detected by touch.

4. Variations in light intensity.

5. Variations in the color, hue or chroma of a light or of an object.

6. Variations in the pitch, fundamental or overtone, of a musical note.

7. Variations in the intensity or loudness of a an electric the pitch orthinking the pitch" of an acceleration-controlled musical note.

In the case of a rapidlyaccelerating elevator, the acceleration being ina straight line, in one dimension only, simple but correlated variationof a single effect, such as change in pitch or in loudness or quality orother characteristic of a musical note, or of any other effect such asthose above listed, is in some cases sufllcient. Preferably the deviceis silent at such times as the elevator is not accelerating ordecelerating.

In the case of a large ocean liner, which rises and falls and rolls, butpitches with only small amplitude or at least without observableforeand-aft acceleration of the passenger, so that the acceleration ischiefly in two dimensionsrone effect can be employed for correlationwith th vertical component of the acceleration and another effect for.the lateral, horizontal component of the acceleration. For example, amusical note can be caused to increase in pitch in correlation withupward acceleration and decrease in pitch with downward acceleration andat the same time increase in intensity in rightward acceleration anddecrease in intensity in leftward acceleration, 75

in Fig. 6 and hereinafter described, but with one of them set in suchattitude as to be responsive to horizontal accelerations and the otherset in such attitude as to be responsive to vertical acceleration. Ordifferent variations of light or color or other eflects can beemployedfor this two dimensional case.

' In the case of substantial acceleration in three dimensions, such asthat to which a passenger may be subject in a badly pitching, rollingand yawing boat or airplane or in a rapidly accelerated and deceleratedautomobile, three varying eflects can be employed for the accelerationsin the respective three dimensions, variations in color produced byeither the individual or the combined effects of lights in the threeprimary colors being an illustrative example, or variations in therelative intensities of three harmonious musical notes. T

The; correlation may be that of a simple ratio,

direct or inverse, or it can be that of any other mathematical function,and even though it is only qualitative and not quantitative, or is thesame for acceleration in either direction, it is helpful in some cases.

Logarithmic correlation has particular value.

The units of loudness of a sound, decibels, for instance, are on alogarithmic scale. Logarithmic increments of pitch are observed as equalintervals.

The phenomena providing the correlated stimuli may be provided invarious ways, as by conscious production of variations of sound or oflight or of color or of dimensional relations by operatives guided bymechanical or electrical means or by their own sensual reactions, butpreferably a dependable and accurate'correlation is provided by theemployment of means independent of the human equation and sensitive toacceleration.

Preferably such means is of a character such as to employ the principleof inertia, and it may conceivably consist of things as recherche as astream of electrically charged particles such as ions or electronsdeflected from their normal path with respect to a target by reason ofthe acceleration, but in many cases the mechanical reaction of a bodyincident to its inertia is the most dependable and reliable origin forthe correlated phenomena or effects, although they may be transmitted ortranslated and made manifest to the observer by either electrical ormechanical or other means, and in some cases an indication of the degreeof acceleration may be given by means other than inertia devices. In anelevator, for instance, the rate of chang of current in the armaturecircuit of the motor is a function of the acceleration. In an automobilethe angle through which the steering wheel is turned is a function ofradial acceleration in rounding a curve. In an airplane, accelerationdepends upon differences of air pressure between th top and bottom wingsurfaces. In a ship, devices detecting the motion of the ship withreference to the water or horizon may be so arranged as to controlcorrelated stimuli.

Many types of apparatus embodying or adapted for the practice of myinvention are possible, some no doubt requiring further invention orinventive improvement and others being obvious from the foregoingstatements. I

Obviously it is impossible to show and describe in this application allof the possible embodiments of my invention, and it is my understandingthat I am required to show and describe only preferred, typicalembodiments of it, and this I do in the accompanying drawings, ofwhich-:

Fig. 1 is a perspective view, with parts broken away, of a preferredembodiment of my invention adapted to cause a spot of light to beprojected on a screen and to change its position on the screen inaccordance with acceleration of the assembly, the device includingmanual control means for providing a test of skill of a personmanipulating the control either for amusement or for lesseningacceleration nausea, in accordance with principles above discussed.

Fig. 1A is a fragmentary perspective view, on a larger scale, of partsshown in Fig. 1.

Fig. 2 is a diagrammatic representation of an assembly adapted to varythe intensity of a light in accordance with acceleration of theassembly.

Fig. 3 is a diagrammatic representation of a somewhat different assemblyfor varying the intensity ofa light in accordance with acceleration.

Fig. 4 is a diagrammatic representation of an assembly adaptedfor'varying the relative intensities of associated lights of differentcolors toproduce variations of color effects, in accordance withvariations of acceleration.

Fig. 5 is a diagrammatic representation of an assembly adapted forproducing a musical note of a pitch varying with acceleration.

Figs. 6 and '7 are diagrammatic representations of assemblies adaptedfor producing a musical note of a loudness varying with acceleration.

Fig. 8 is an elevation, with a part broken away, of an assembly adaptedfor manipulating the volume control of a radio in accordance withacceleration.

Referring to the drawings, and at first to Figs. 1 and 1A, the devicethere shown comprises a cabinet l having mounted on one end of it ascreen Ii adapted to receive a beam of light, through a hole 12 in theroof of the cabinet, from a source of light within the cabinet. Thescreen preferably is so marked, as by crossed lines l3, l4, as toprovide a central target, upon which the person operating the control isto try to keep the beam of light in spite of acceleration of theassembly and of the person, as in case the device is used upon a ship.The screen preferably is provided also with a hood I for par tiallyexcluding other light so that the beam will show clearly upon the screeneven though the room is not darkened.

The assembly within the cabinet for providing the beam of lightcomprises an initial light source such as the electric bulb IS, aparabolic reflector I! for reflecting the part of the light that itreceives, with concentration of the rays, to a lens assembly 18 adaptedto pass the rays, in substantial parallelism, to a reflector l9 whichreflects it upon the screen II.

This reflector I9 is mounted upon the end of a small spring wire 20which at its other end, in this particular embodiment, is fixedlysecured to a head 2| which is fixedly secured to the top of a relativelystiff spring post 22 mounted upon the floor of the cabinet, the head 2|having fixed to it a hand-control arm 23 projecting to the exterior ofthe cabinet through a hole in the front wall of the latter, the arm 23permissibly being slightly springy for slowness of response of theinertia member 24, described below and reflector, if that is desired. Byreason of the arms 20 and 23 being fixed in relation to the spring post22 large amplitude displacement of the handle and comparatively largeeffort are required for small amplitude relative displacement of theinertia member 24. e

To cause the reflector H to lag, and also to change its relativeorientation somewhat, and

thus change the position of the spot of light on the screen, as theassembly accelerates to the right or to the left or upward or downward,as in the case of the motion of a ship in a heavy sea, the spring wire.20 has secured thereon an inertia member, here shown as being in theform' of a disc 24 (Fig. 1A) which, for reasons that will presentlyappear, is preferably of copper or other highly conductive andnon-magnetic material, in this particular embodiment.

For damping oscillations of the spring wire and the inertia member andthe reflector mounted thereon if it is desired that the skill requiredfor good control of the light beam be not too great, two U-magnets 25,26 are mounted upon a floor standard 21 and are connected by iron rings28, 29 which are positioned on opposite sides of and slightly spacedfrom the disc shaped inertia member 24.

As will be understood by those skilled in the art, movement of theinertia member with relation to the magnet assembly, as the spring wire20 bends, causes the generation of eddy currents in the disc 24, and theenergy absorbed thereby thus provides the damping effect.

The mode of operation of this device has already been brought out, inthe introduction to the specification and in the above description, andso fully, it is believed, that further recital of it at this point wouldbe annoyingly repetitious.

In the assembly illustrated in Fig. 2 the intensity of the light of anelectric bulb 30 is varied in accordance with variations of accelerationby varying the current flowing through an alternating current circuit 3|in which the light is mounted, this being accomplished by means of anacceleration-sensitive relay. This relay comprises a core 32 of magneticmaterial having thereon a winding 3| in series with the light, and,hinged at 33 on a standard 34, an armature 35 of magnetic material. Ahelical compression spring 36 is so mounted as to support the armatureagainst gravity and against inertia of the armature in upwardacceleration of the assembly and at such an elevation as to maintainbetween the core and the armature an air gap which varies in width inaccordance with upward and downward acceleration of the assembly becauseof variation of the armature's inertia as a factor in increasing ordiminishing the total load upon the spring. A weight 31 may beadjustably secured upon the armature, as by a set-screw 38, for ineffect increasing the inertia of the armature and also for adjustment ofthe width of the air gap at zero acceleration.

In the operation of this assembly, variation in the width of the air gapproduces corresponding changes in the reactance of the winding 3| uponthe core 32 and in the current flowing through the light.

The assembly shown in Fig. 3 is adapted for use with direct current, thearrangement being substantially the same as that oi Fig. 2 except that acarbon pile variable resistance 88 mounted in series with the light isused instead of the reactance device oi! Fig. 2 and a hinged arm 35"having a weight 81 adjustably secured thereon is adapted to vary itspressure upon the carbon pile in accordance with variations of accelera-4 tion, a compression spring 88' being so mounted mounted in a glasslight bowl 48, which may be frosted or not, as desired.

The intensity of the light of the bulb 48 is modified by a device 44,which is here shown as being of the same type as that shown in Fig. 2,mounted to be sensitive to vertical accelerations and decelerations; theintensity of the light of the bulb 42 is modified by a device 45, hereshown as being of the same type, mounted to be sensitive toaccelerations and decelerations in directions transverse to aship, forexample; and the intensity of the light of the bulb 4! is modified by adevice 48, here shown as being of the same type as that of Fig. 2,mounted to be sensitive to accelerations and decelerations in directionslengthwise of the ship.

The assembly of Fig. 5 is adapted to produce a musical note varying withacceleration and comprises a well known vacuum tube oscillatingregenerative circuit in which the frequency is changed by varying thereactance oi! the so-called tank circuit by means of an inertia member.This oscillating circuit supplies electrical energy through suitableamplifying means to operate a loud-speaker or telephone head-set andproduce a musical note of a pitch corresponding to the frequency ofoscillation.

In this assembly of Fig. 5 a tube 41 of the well known pentode type isshown, although my invention is not wholly limited to that particulartype of the several types of tubes commonly used in such circuits. Theplate of the tube is connected to one side of a condenser 48 and of awinding 49 on the core of a variable reactor 58, and the other side ofthe condenser 48 and winding 48 are connected together and to thepositive terminal of a source 5| of B voltage supply. The negativeterminal of this B voltage supply is connected to the ground and to thecathode 52 through a resistor 53 and by-pass condenser 54 according tousual practice.

Winding 48 and condenser 48 constitute the tank circuit of theoscillator and variations of the inductance of this winding will, as iswell known, cause a variation in the frequency of oscillation.

producing device such as the loud-speaker 82. It will be obvious that byproper selection oi the various constants of the circuit a pleasingmusical note can be reproduced.

I! desired, harmonics may be introduced by various well-known methods toobtain various desired qualities of tone.

Numerous modifications of this assembly will be obvious to those skilledin the electrical art.

The assembly of Fig. 6 is adapted for producing a musical note oi fixedpitch but of intensity varying with variations of acceleration.

The arrangement includes an oscillating circuit with a magnetic balancerelay operated by an inertia member.

The plate or a triode tube 88 is connected to one end of a winding 84and one side 01 condenser 85. A winding 88 is connected in series withwinding 84 and joined to the other side of condenser 85 and to thepositive terminal of a B power supply 81. The negative terminal or thisB supply is connected to the cathode 88 according to usual practice.

windings 88 and 18, in series, furnish the feed back to the grid,through the usual grid leak 'H and the condenser I2.

windings 84 and 85, oncores l8 and 18, with condenser 85, constitute thetank circuit of the oscillator. The current circulating through thesecoils causes a flux to flow through the cores l8 and 18 and across theair gaps.

Coils l3 and 14 in series, wound upon armature 15 constitute the powerpick-up, connected through amplifier 18 to the sound producing device11.

If the number of turns on coil 84 is equal to the number of turns oncoil 88 and the armature 15 is exactly at the center between the twocores, no flux flows through the armature and no current will be inducedin the pick up coils l8 and 14, and the sound producing device will thenbe silent.

If, however, the armature I5 is moved slightly oil center a flux willflow through the armature, causing a current to be induced in the pickup coils and a sound to be produced in the sound producing device, theloudness of which will depend upon the amount of displacement of thearmature from center.

Thus the arrangement will produce no sound at zero acceleration and anincreasing loudness of sound with increase in magnitude of accelerationregardless of the direction of this acceleration;

By proper proportioning of the number of turns in coils 84 and 85 it ispossible to bring the neutral point of no-sound at any position oi theThis variation is obtained, as explained above,

armature. With the armature at center there would be then a definitesound produced. Acceleration in one direction would then increase theloudness of the sound and in the other direction reduce this loudness.

In this assembly of Fig. 6, the armature I5 is, at zero acceleration,held at a determinate position bycompression springs 88, 8| and, for ineffect increasing its inertia and for damping periodic oscillations ofthe resilient assembly a weight structure having dash-potcharacteristics is secured to one end of the armature. This weight anddash-pot structure comprises a iluid tight casing 82 and, slidablymounted therein, a hollow, open ended weight member 83, which, at zeroacceleration, is held at an intermediate position in the casing by ahelical compression spring 84 seated uponthe floor of the casing and atits upper end bearing against a partition 85 which is a part of theweight member and is formed with a dash-pot aperture". Completelyfilling or substantially filling the casing and weight member is adash-pot liquid 91, which may be water, oil or the like.

In upward or downward acceleration of the assembly the acceleration ofthe weight member 93 will be resisted by its inertia except as theliquid, with a dash-pot effect, fiows through the hole 96 in thepartition, the absorption of energy in the internal friction ofthe'liquid providing the damping eilect. 9

Internal friction of the fiuid flowing through the aperture absorbspotential energy of the springs 99, 9] and thus clamps their periodicoscillation. At zero acceleration the spring 94, or gravity, of coursethen moves the weight member toward its normal intermediate position,for effective dash-pot action in the next acceleration.

Fig. '7 illustrates another arrangement to produce a sound of constantpitch and of loudness varying with acceleration. This arrangementcomprises a stabilized oscillator 99 for producing oscillating currentat suitable constant frequency, a volume control 9| actuated by aninertia member 92, a. suitable amplifier 93, if required, and a soundproducing device 94.

The inertia operated volume control consists of a resistance 95connected across the output of oscillator 99, and a sliding-contactlever arm 95 articulated at 91, reacting against springs 99 and 99, andhaving sliding contact on resistor 95.

It will be seen that the voltage input into the amplifier, between wiresI94 and I95, will depend upon the point of contact, of sliding contact96 and resistor 95, and therefore upon the-value of acceleration actingupon the inertia member 92.

It will be obvious that by proper graduation of the resistance along thepath of the sliding contact in proportion to the size of the inertia Imember 92 or the strength of the springs 99 and 99, various desirablerelations between acceleration and loudness can be obtained.

Obviously a variable pitch generator such as described in Fig. 5 couldbe substituted for the constant pitch generator 99 to produce avariation of both pitch and loudness with variations of acceleration.

In Fig. 8 the volume-control stem I96 of a radio receiving set hassecured thereon a pinion I91 which is meshed with a gear-segment I98formed on a lever I99 which is pivoted on the frame of the set at H9 andserves as an inertia member as to vertical accelerations, the leverbeing provided with a helical pull spring ill for holding it at anintermediate position when there is no acceleration.

Obviously, as in the case of a blind and deaf person, the sense of touchor of feeling could be employed for correlation, by means of theapparatus of any of the figures of the drawings.

With the device of Fig. 2, for example, an artificially modified andmagnified manifestation of inertia effects of the acceleration, throughthe sense of feeling, could be obtained either by manually feeling themovement of the armature 35 in relation to the core 32 or by manuallyfeeling the changes in temperature of the bulb 39. In the latter casethere would be a slight time lag, but nevertheless the person in whomseasickness was being combated could discern and establish in hisconsciousness a continuing correlation between the rhythmic changes oftemperature and the rhythmic accelerations of a rolling ship.

Another example is that with the device of Fig. 8 an artificiallymodified and magnified manifestion of inertia effects of theacceleration. through the sense of feeling, could be obtained bymanually feeling the movement of the coils of the spring III in relationto'each other or by placing a finger in the bite of the gear members I91and I99.

In all of the devices shown and described,

the manifestation of the inertia effects of the acceleration is anartificially modified and magnified manifestation.

Many other modifications are possible within the scope of my inventionas defined by the appended claims.

I claim:

1. Apparatus for combating acceleration nausea, said apparatuscomprising artificial means for detecting acceleration and meansactuated thereby for presenting a magnified manifestation of inertiaeffects of the acceleration. through the sense of sight, to the personinvolved.

2. Apparatus for combating acceleration nausea, said apparatuscomprising inertia means for detecting accelerationas to direction inmore than one of the three dimensions and means actuated thereby forpresenting a magnified mamfestation of the acceleration, as todirection, in more than one of the three dimensions, and through a senseother than the sense of acceleration of the inner ear, to the personinvolved.

3. Apparatus for combating acceleration nausea, said apparatuscomprising artificial means for detecting acceleration and meansactuated thereby for presenting a magnified manifestation of inertiaefiects of the acceleration, through a sense other than the sense ofacceleration of the inner ear, to the person involved, th manifestationbeing visual and being dimensional with relation to a visual datumpoint.

. 4. Apparatus for combating acceleration nausea, said apparatuscomprising artificial means for detecting acceleration, means actuatedthereby for'manifesting the acceleration, through a sense other than thesense of acceleration of the inner ear, to the person involved, andmeans subject to the control of said person'for manifesting hisapprehension of the acceleration through'the said artificial means.

5. Apparatus for combating acceleration nausea, said apparatuscomprising artificial means for detecting acceleration, mean actuatedthereby for manifesting the acceleration, through a sense other than thesense of acceleration of the inner ear, to the person involved, andmeans subject to the control of said person for manually manifesting hisapprehension of the acceleration through the said artificial means.

' 6. Apparatus for combating acceleration nausea, said apparatuscomprising artificial means for detecting acceleration as to directionand intensity, means actuated thereby for manifestin the acceleration asto direction and intensity, through a sense other than the sense ofacceleration of the inner ear, to the person involved, and means subjectto the control of said person for manifesting hisapprehension of theacceleration as to direction and intensity through the said artificialmeans.

7. Apparatus for combating acceleration nausea, said apparatuscomprising artificial means for detecting acceleration as to directionand intensity, means actuated thereby for manifesting the accelerationas to direction and intensity,throushasenseotherthanthesenseotacceleration'oi the inner ear. to theperson involved, and means subject to the control of said person formanually manifesting his apprehension of the acceleration as todirection and intensity throush the said artificial means.

8. Apparatus for combating acceleration nausea, said appa atuscomprising an inertia memher for detecting acceleration, means actuatedthereby ior'manii'esting the acceleration, through a sense other thanthe sense or acceleration oi the inner ear, to the person involved,yielding means for maintaining said inertia member at an intermediateposition at zero acceleration, and means for damping oscillations orsaid inertia member.

9. Apparatus for combating acceleration nau. sea. said apparatuscomprising a screen, an inertia member, and means primarily controlledby the inertia member for casting a beam of light upon the screen andmoving it thereon in determinate relation to changes 0! acceleration ofthe assembly.

10. Apparatusior combating acceleration nausea, said apparatuscomprising a screen, an inertia member, means primarily controlled bythe inertia member for casting a beam of light upon the screen andmoving it thereon in determinate relation to changes of acceleration ofthe assembly, and means subject to manual control for modifying theeilect or the inertia member upon the said beam casting means.

ROBERT MAYNE.

